Recent Notes

Displaying keyword search results 1 - 10
Created by Fang on March 30, 2012 10:07:25    Last update: March 08, 2013 13:41:57
After a user resets a password, I want to force the user to change the password before she gets access to secured content. This is usually done with a servlet filter. But with Spring MVC, you can also use a HandlerInterceptor . According to Spring JavaDoc: HandlerInterceptor is basically similar to a Servlet 2.3 Filter, but in contrast to the latter it just allows custom pre-processing with the option of prohibiting the execution of the handler itself, and custom post-processing. Filters are more powerful, for example they allow for exchanging the request and response objects that are handed down the chain. Note that a filter gets configured in web.xml, a HandlerInterceptor in the application context. As a basic guideline, fine-grained handler-related preprocessing tasks are candidates...
Created by freyo on September 07, 2011 16:46:14    Last update: September 07, 2011 19:23:00
The Android unit test framework is based on JUnit 3 , not JUnit 4. Test cases have to extend junit.framework.TestCase or a subclass (such as android.test.InstrumentationTestCase ). Tests are identified by public methods whose name starts with test , not methods annotated with @Test (as in JUnit 4). An Android test suite is packaged as an APK, just like the application being tested. To create a test package, first you need to identify the application package it is testing. Google suggests to put the test package source in a directory named tests/ alongside the src/ directory of the main application. At runtime, Android instrumentation loads both the test package and the application under test into the same process. Therefore, the tests can invoke methods on...
Created by freyo on August 17, 2011 12:29:46    Last update: August 17, 2011 12:29:46
In Android.mk , you can define LOCAL_JARJAR_RULES like this: LOCAL_JARJAR_RULES := $(LOCAL_PATH)/jarjar-rules.t... and in jarjar-rules.txt define a rule like this: rule org.bouncycastle.** com.android.@0 The build will change all org.bouncycastle to com.android.org.bouncycastle . Therefore, in your classes which are dependent on the library produced, the import statements should look like: import com.android.org.bouncycastle... Help for the jarjar utility (in prebuilt/common/jarjar/ ): $ java -jar jarjar-1.0rc8.jar Jar Jar Links - ...
Created by Dr. Xi on April 26, 2011 20:12:01    Last update: April 28, 2011 15:28:12
An XML schema is a definition of XML files, in XML. It plays the same role as old-time DTDs. Overall, an XML schema file looks like this: <schema attributeFormDefault = (qualified | u... The attribute meanings: targetNamespace : The name space targeted by the current schema definition. It can be any URI. id and version : For user convenience, the W3C spec defines no semantics for them. xml:lang : Natural language identifier defined by RFC 3306 . attributeFormDefault and elementFormDefault : Set default values for the form attribute for attribute and element declarations. blockDefault and finalDefault : Set default values for the block and final attributes for attribute and element declarations. The W3C defined some built-in datatypes . Examples of primitive datatypes are: string ,...
Created by nogeek on November 11, 2010 00:26:08    Last update: November 11, 2010 00:29:43
This one is even more weird: it worked on Windows but failed on Linux, using default tools JDK1.6.0_20 on both. The exception thrown was: java.lang.RuntimeException: Invalid conversion fro... And the stack trace: java.lang.RuntimeException: Invalid conversion fro... This was the XSL used: <?xml version="1.0" encoding="ISO-8859-1"?> <xs... The problem was , DateUtil.java had two getDate methods, one taking long parameter, the other taking a String parameter. And Java's XSLT get confused about which one to use: import java.util.Date; import java.text.SimpleD...
Created by Dr. Xi on October 26, 2010 16:07:40    Last update: October 26, 2010 16:07:40
This is a more generic version, which can be expanded to accommodate additional file signatures. import java.io.*; import java.util.*; pu...
Created by Fang on August 10, 2010 21:37:36    Last update: October 25, 2010 20:18:47
The tags <fmt:formatNumber> Format a numeric value as number , currency or percentage - controlled by the type attribute (defaults to number if type is missing). Syntax: <fmt:formatNumber value="numericValue" [type="... Attributes: Name Dynamic? Type Description value true String or Number Numeric value to be formatted. type true String Specifies whether the value is to be formatted as number, currency, or percentage. pattern true String Custom formatting pattern, must follow the pattern syntax specified by the class java.text.DecimalFormat . currencyCode true String ISO 4217 currency code. Applied only when formatting currencies (i.e. if type is equal to "currency"); ignored otherwise. currencySymbol true String Currency symbol. Applied only when formatting currencies (i.e. if type is equal to "currency"); ignored otherwise. It is used only when currencyCode is...
Created by Dr. Xi on July 29, 2010 18:46:57    Last update: July 29, 2010 18:48:15
This is an example of using java.beans.XMLEncoder and java.beans.XMLDecoder to serialize/deserialize Java objects to XML. Java code TestXMLEncoder.java: import java.io.*; import java.beans.XMLEncoder;... SimpleBean.java: public class SimpleBean { private String na... CompositeBean.java: public class CompositeBean { private Simple... NotABean.java: public class NotABean { private String name... Test Output By default, only Java beans can be serialized using XMLEncoder . Exception occurs when you try to deserialize an object which is not a Java bean. Errors actually occur when you try to serialize, but they are ignored. As a result, an XML file is generated by the serialization but the file is useless! Console output: C:\>java TestXMLEncoder Testing simple bean ... simplebean.xml: <?xml version="1.0" encoding="UTF-8"?> <java v... compositebean.xml: <?xml version="1.0" encoding="UTF-8"?> <java v... nodefault.xml: <?xml version="1.0" encoding="UTF-8"?> <java v......
Created by Fang on April 04, 2010 04:12:14    Last update: July 21, 2010 14:52:58
The tags <c:if> The <c:if> tag may be used with or without body content: <!-- Without body content, used to export vari... In my opinion, the version without body content is pretty much useless (the <c:set> tag is a lot more meaningful for this purpose). If body content exists, it is inserted into the page if the testCondition is true . Optional attributes var and scope may be specified. If var is specified, a variable whose name is the value of var is exported to the associated scope ( pageScope if no scope is specified). The type of the exported variable is Boolean and its value is the value of the testCondition . <c:choose>, <c:when>, <c:otherwise> These tags imitate the Java control structure if...else...
Created by Dr. Xi on October 06, 2008 18:39:53    Last update: October 06, 2008 18:39:53
Python modules are searched in the list of directories given by the variable sys.path which is initialized from: the directory containing the input script (or the current directory) the list of directories specified by the environment variable PYTHONPATH the installation-dependent default. peaches@bashful:~/tmp$ export PYTHONPATH=`pwd` ...